Summary

HandWiki is the world's largest wiki-style encyclopedia dedicated to science, technology and computing. It allows you to create and edit articles as long as you have external citations and login account. In addition, this is a content management environment that can be used for collaborative editing of original scholarly content, such as books, manuals, monographs and tutorials.

Expand All
Entries
Topic Review
Forensic Epidemiology
The discipline of forensic epidemiology (FE) is a hybrid of principles and practices common to both forensic medicine and epidemiology. FE is directed at filling the gap between clinical judgment and epidemiologic data for determinations of causality in civil lawsuits and criminal prosecution and defense. Forensic epidemiologists formulate evidence-based probabilistic conclusions about the type and quantity of causal association between an antecedent harmful exposure and an injury or disease outcome in both populations and individuals. The conclusions resulting from an FE analysis can support legal decision-making regarding guilt or innocence in criminal actions, and provide an evidentiary support for findings of causal association in civil actions. Applications of forensic epidemiologic principles are found in a wide variety of types of civil litigation, including cases of medical negligence, toxic or mass tort, pharmaceutical adverse events, medical device and consumer product failures, traffic crash-related injury and death, person identification and life expectancy.
  • 891
  • 23 Nov 2022
Topic Review
Immunity (Medical)
In biology, immunity is the capability of multicellular organisms to resist harmful microorganisms. Immunity involves both specific and nonspecific components. The nonspecific components act as barriers or eliminators of a wide range of pathogens irrespective of their antigenic make-up. Other components of the immune system adapt themselves to each new disease encountered and can generate pathogen-specific immunity. Immunity is a complex biological system that can recognize and tolerate whatever belongs to the self, and to recognize and reject what is foreign (non-self).
  • 1.8K
  • 23 Nov 2022
Topic Review
Capella (Engineering)
Capella is an open-source solution for model-based systems engineering (MBSE). Hosted at polarsys.org, this solution provides a process and tooling for graphical modeling of systems, hardware or software architectures, in accordance with the principles and recommendations defined by the Arcadia method. Capella is an initiative of PolarSys, one of several Eclipse Foundation working groups.
  • 1.5K
  • 23 Nov 2022
Topic Review
Galápagos Islands
The Galápagos Islands (official name: Archipiélago de Colón, other Spanish name: Las Islas Galápagos, Spanish pronunciation: [las ˈislas ɣaˈlapaɣos], local pronunciation: [laz ˈihlah ɣaˈlapaɣoh]), part of the Republic of Ecuador, are an archipelago of volcanic islands distributed on either side of the equator in the Pacific Ocean surrounding the centre of the Western Hemisphere. Located 906 km (563 mi) west of continental Ecuador, the islands are known for their large number of endemic species that were studied by Charles Darwin during the second voyage of HMS Beagle. His observations and collections contributed to the inception of Darwin's theory of evolution by means of natural selection. The Galápagos Islands and their surrounding waters form the Galápagos Province of Ecuador, the Galápagos National Park, and the Galápagos Marine Reserve. The principal language on the islands is Spanish. The islands have a population of slightly over 25,000. The first recorded visit to the islands happened by chance in 1535, when Fray Tomás de Berlanga, the Bishop of Panamá, was surprised with this undiscovered land during a voyage to Peru to arbitrate in a dispute between Francisco Pizarro and Diego de Almagro. De Berlanga eventually returned to the Spanish Empire and described the conditions of the islands and the animals that inhabited them. The group of islands was shown and named "Insulae de los Galopegos" (Islands of the Tortoises) in Abraham Ortelius's atlas published in 1570. The first crude map of the islands was made in 1684 by the buccaneer Ambrose Cowley, who named the individual islands after some of his fellow pirates or after British royalty and noblemen. These names were used in the authoritative navigation charts of the islands prepared during the Beagle survey under captain Robert FitzRoy, and in Darwin's popular book The Voyage of the Beagle. The newly independent Republic of Ecuador took the islands from Spanish ownership in 1832, and subsequently gave them official Spanish names. The older names remained in use in English-language publications, including Herman Melville's The Encantadas of 1854. Administratively, Galapagos constitutes one of the provinces of Ecuador, made up of three cantons that bear the names of its most populated islands, namely: San Cristóbal, Santa Cruz and Isabela.
  • 2.1K
  • 23 Nov 2022
Topic Review
Agorism
Agorism is a libertarian social philosophy that advocates creating a society in which all relations between people are voluntary exchanges by means of counter-economics, thus engaging with aspects of peaceful revolution. It was first proposed by libertarian philosopher Samuel Edward Konkin III at two conferences, CounterCon I in October 1974 and CounterCon II in May 1975, both conferences organized by J. Neil Schulman.
  • 8.7K
  • 23 Nov 2022
Topic Review
Cell
The cell (from the Latin word cellula meaning 'small room') is the basic structural and functional unit of life forms. Every cell consists of a cytoplasm enclosed within a membrane, which contains many biomolecules such as proteins and nucleic acids. Cells can acquire specified function and carry out various tasks within the cell such as replication, DNA repair, protein synthesis, and motility. Cells are capable of specialization and mobility within the cell. Most cells are measured in micrometers due to their small size. Most plant and animal cells are only visible under a light microscope, with dimensions between 1 and 100 micrometres. Electron microscopy gives a much higher resolution showing greatly detailed cell structure. Organisms can be classified as unicellular (consisting of a single cell such as bacteria) or multicellular (including plants and animals). Most unicellular organisms are classed as microorganisms. The number of cells in plants and animals varies from species to species; it has been approximated that the human body contains an estimated 37 trillion (3.72×1013) cells. The brain accounts for around 80 billion of these cells. The study of cells and how they work has led to many other studies in related areas of biology, including: discovery of DNA, cancer systems biology, aging and developmental biology. Cell biology is the study of cells, which were discovered by Robert Hooke in 1665, who named them for their resemblance to cells inhabited by Christian monks in a monastery. Cell theory, first developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all living organisms, and that all cells come from pre-existing cells. Cells emerged on Earth about 4 billion years ago.
  • 3.2K
  • 23 Nov 2022
Topic Review
Artemisia Australis
Artemisia /ˌɑːrtɪˈmiːziə/ is a large, diverse genus of plants with between 200 and 400 species belonging to the daisy family Asteraceae. Common names for various species in the genus include mugwort, wormwood, and sagebrush. Artemisia comprises hardy herbaceous plants and shrubs, which are known for the powerful chemical constituents in their essential oils. Artemisia species grow in temperate climates of both hemispheres, usually in dry or semiarid habitats. Notable species include A. vulgaris (common mugwort), A. tridentata (big sagebrush), A. annua (sagewort), A. absinthium (wormwood), A. dracunculus (tarragon), and A. abrotanum (southernwood). The leaves of many species are covered with white hairs. Most species have strong aromas and bitter tastes from terpenoids and sesquiterpene lactones, which discourage herbivory, and may have had a selective advantage. The small flowers are wind-pollinated. Artemisia species are used as food plants by the larvae of a number of Lepidoptera species. Some botanists split the genus into several genera, but DNA analysis does not support the maintenance of the genera Crossostephium, Filifolium, Neopallasia, Seriphidium, and Sphaeromeria; three other segregate genera -- Stilnolepis, Elachanthemum, and Kaschgaria -- are maintained by this evidence. Occasionally, some of the species are called sages, causing confusion with the Salvia sages in the family Lamiaceae.
  • 1.1K
  • 23 Nov 2022
Topic Review
Electrically Powered Spacecraft Propulsion
An electrically powered spacecraft propulsion system uses electrical, and possibly also magnetic fields, to change the velocity of a spacecraft. Most of these kinds of spacecraft propulsion systems work by electrically expelling propellant (reaction mass) at high speed. Electric thrusters typically use much less propellant than chemical rockets because they have a higher exhaust speed (operate at a higher specific impulse) than chemical rockets. Due to limited electric power the thrust is much weaker compared to chemical rockets, but electric propulsion can provide thrust for a longer time. Electric propulsion is now a mature and widely used technology on spacecraft. Russia n satellites have used electric propulsion for decades. (As of 2019), over 500 spacecraft operated throughout the Solar System use electric propulsion for station keeping, orbit raising, or primary propulsion. In the future, the most advanced electric thrusters may be able to impart a delta-v of 100 km/s, which is enough to take a spacecraft to the outer planets of the Solar System (with nuclear power), but is insufficient for interstellar travel. An electric rocket with an external power source (transmissible through laser on the photovoltaic panels) has a theoretical possibility for interstellar flight. However, electric propulsion is not suitable for launches from the Earth's surface, as it offers too little thrust. On a journey to Mars, an electrically powered ship might be able to carry 70% of its initial mass to the destination, while a chemical rocket could carry only a few percent.
  • 1.8K
  • 23 Nov 2022
Biography
William Robert Graham
William Robert Graham (born June 15, 1937) is an American physicist who was Chairman of President Reagan's General Advisory Committee on Arms Control from 1982 to 1985, a Deputy Administrator and Acting Administrator of NASA during 1985 and 1986, and Director of the White House Office of Science and Technology Policy and concurrently Science Adviser to President Reagan from 1986 to 1989. He then
  • 1.1K
  • 23 Nov 2022
Topic Review
African Golden Wolf
The African golden wolf (Canis lupaster) or African wolf is a canine native to North Africa, West Africa, the Sahel, northern East Africa, and the Horn of Africa. It is the descendant of a genetically admixed canid of 72% gray wolf (Canis lupus) and 28% Ethiopian wolf (Canis simensis) ancestry. It is listed as least concern on the IUCN Red List. In the Atlas Mountains, it was sighted in elevations as high as 1,800 m (5,900 ft). It is primarily a predator, targeting invertebrates and mammals as large as gazelle fawns, though larger animals are sometimes taken. Its diet also includes animal carcasses, human refuse, and fruit. The African golden wolf is a monogamous and territorial species; offspring remain with the family to assist in raising their parents' younger pups. It was previously classified as an African variant of the golden jackal (Canis aureus), with at that time at least one subspecies (C. a. lupaster) having been classified as a wolf. In 2015, a series of analyses on the species' mitochondrial DNA and nuclear genome demonstrated that it was, in fact, distinct from the golden jackal, and more closely related to the gray wolf and the coyote (Canis latrans). It is nonetheless still close enough to the golden jackal to produce hybrid offspring, as indicated through genetic tests on jackals in Israel, and a 19th-century captive crossbreeding experiment. It plays a prominent role in some African cultures; in North African folklore, it is viewed as an untrustworthy animal whose body parts can be used for medicinal or ritualistic purposes, while it is held in high esteem in Senegal's Serer religion as being the first creature to be created by the god Roog.
  • 7.0K
  • 23 Nov 2022
  • Page
  • of
  • 863

Other Entry Collections

>>